A (writ of) mandamus is an order from a court to an inferior government official ordering the government official to properly fulfill their official duties or correct an abuse of discretion. It can be filed without a lawyer, but I'm not sure that it's the right procedure unless you're trying to get a court to make the administrative agency follow its rules or to enforce its administrative procedures.

If you file without a lawyer, it will be taken as serious as if a lawyer filed it.....but you just have to be able to handle the procedures on your own (as you'd be held to the same standard as a lawyer in handling the case).